“To find a more independent estimate of the scope of daily oil spills, the report’s authors drew on an analysis of that same NRC data by SkyTruth, a nonprofit that uses satellite imagery—mainly from the European Space Agency, one of the few free resources—to monitor the environmental effects of industrial activity. Using SkyTruth’s numbers, report authors say the total amount of oil spilled in the northern Gulf last year was closer to 875,000 gallons, or about 50 times larger than official estimates.”